Air turning vane with removable closure for insertion of acoustical material



y 5, 1969 G. R. JACOBSEN 3,455,412

AIR TURNING VANE WITH REMOVABLE CLOSURE FOR INSER'IION.

OF ACOUSTICAL MATERIAL Filed Jan. 10, 1968 INVENTOR GORDON R. JACOBSEN M, XW

ATI'O RN EYS United States Patent AIR TURNING VANE WITH REMOVABLE CLOSURE FOR INSERTION 0F ACOUSTICAL MATERIAL Gordon R, Jacobson, 4248 Newherry Court, Palo Alto, Calif. 94306 Filed Jan. 10, 1968, Ser. No. 696,833 Int. Cl. F01n 1/10 US. Cl. Isl-50 8 Claims ABSTRACT OF THE DISCLOSURE A hollow turning vane of generally airfoil crosssectional contour having sound-absorbing material therein for inhibiting the generation of sound by the vane during flow of air therepast, which vane is constructed to provide an open side through which said sound-absorbing material may be inserted into the vane, in the making of the latter, and a closure for such side that comprises one side of the vane and that includes means, in association with the remainder of the vane, and with a securing means securing the vane in a conduit or duct.

Background of invention Hollow turning vanes in themselves are old, but heretofore the manufacture of hollow vanes filled with soundabsorbing material, such as fiber glass. has been expensive from the standpoint of labor and material, and the vanes have not been uniformly satisfactory.

Turning vanes of this invention, and those in the prior art that incorporate structure intended to absorb sound generated in the vane or otherwise, will be called acoustical vanes. In modern practice, acoustical hollow turning vanes are elongated and their outer surfaces are concave-convex in cross-sectional contour transversely of the length between parallel side edges. Usually such vanes have been symmetrical at opposite sides of a medial plane parallel with and between said side edges, and at least one side of the vane has been formed by extrusion, with means on the side so extruded for securement to the opposite sides of an elbow of a duct, or to rails that, in turn, are secured within a duct.

The present turning vane eliminates any extruded portions and provides a pair of connected strips of sheet metal of arcuate cross-sectional contour, adapted to be quickly assembled with the sound-absorbing insulation material of uniform thickness held between them. The means for securing the two strips together also provides one of the means for securing the vane in a duct or to rails, and for holding the two strips of each vane firmly together.

Summary The structure of the present invention provides a hollow vane of generally airfoil cross-sectional contour, in which a pair of concave-convex strips are connected along their opposite longitudinally extending edges, and are simultaneously curved in said cross-sectional contour but are progressively spaced apart in directions from their connected edges toward each other, and one strip is formed with an opening extending longitudinally of said edges for insertion of sound insulation material between said strips. A closure is adapted to be sprung into interengaging relation with said one strip to close the opening, and the means for holding said strips together provides means for also securing each vane between rails or vane supporting means, and for tightening the connection between the closure and said one of said strips.

Description of drawings In the drawings, FIG. 1 is a small semi-diagrammatic view of several vanes of the present structure in the elbow of an air duct, the Walls of the vanes being indicated in single lines and the elbow of the duct being in cross section.

FIG. 2 is an enlarged, fragmentary, isometric crosssectional view through a vane transversely of its length and in an inverted position for assembly of the parts of the vane with fragments of pressing elements used in assembling the parts being indicated.

FIG. 3 is a reduced size view of several vanes as seen from line 3-3 of FIG. 4 in position between a pair of rails to which they are secured, with one of the rails being partially broken away in length.

FIG. 4 is a view of several vanes as seen at a right angle to the position in FIG. 3, one of the vane-securing nails being indicated separate from the vanes and rails and in a position for being driven through one of the rails into an opening in one of the vanes.

FIG. 5 is an enlarged exploded view of one of the two corresponding structures for holding the strips of each vane together, the two portions being identical, as seen in FIG. 2.

FIG. 6 is a view similar to that of FIG. 5 but in which the two parts are secured together.

Description of invention In FIG. 1 an elbow, generally designated 1, is of rectangular cross-sectional contour, the near side being broken away to show one of the rails 2 and the turning vanes 3 in full line.

The rails 2 are strips between which the vanes extend and to which they are secured, as will be explained later on more in detail.

Each vane comprises an inner strip 4, and an outer strip 5, the strip 4 being called the inner strip, inasmuch as in each vane, it is positioned nearest the inside corner of the elbow when in the latter, while the strip 5 is nearest the outside corner of the elbow.

When the strips are secured together they provide a hollow vane, the outline of which, in cross-sectional contour is that of a modified airfoil having a forward portion generally designated 6 with a rounded, relatively blunt, forward edge 7 and a more flattened trailing or rear portion 8 with a sharper trailing or rear edge 9.

The inner and outer strips are arcuate in cross-sectional contour and are similarly curved intermediate the forward and rear edges of the vane, in that the concave surfaces of the two strips face in the same direction. The are of the inner strip 4 is relatively shallow compared with the arc of the outer strip 5, hence the spacing between the strips progressively increases from the edges 7 and 9 toward each other, with the maximum spacing being closer to edge 7 than edge 9.

The words forward and rear, and other words of similar connotation are used with respect to the direction of flow of air in the duct, the forward edge is the edge facing oppositely to the direction of flow, while the rear edge faces in the direction of flow. Thus, the deflection efiiciency of the present vanes is substantially greater than that of the conventional sharp-edged vanes.

Strips 4 and 5 are separately formed, and the blunt, rounded forward edge 7 and the less blunt or sharper rear edge 9 of the vane, are formed from strip 5 and define return bends in strip 5 by bending the marginal portions 10, 11 of strip 5 along the side edges thereof toward each other to opposed spaced relation to the sur- 3 faces of strip 5 on the concavely curved side of the latter (FIG. 2).

The marginal portion is of less width than marginal portion 11, and the parts respectively along the terminal longitudinally extending edges of marginal portions 10, 11 of strip 5 are bent to form a pair of corresponding channels 14 (FIGS. 2, 5) having substantially cylindrical walls that project toward the body of strip 5 opposed thereto. The open sides 15 of the channels 14 face away from the body of strip 5 and one edge of the open side 15 of each channel is along the juncture between each channel and the marginal portions 10, 11, respectively, while the opposite edge is the terminal edge of each marginal portion 10, 11.

From the foregoing description it is seen that the strip 5, itself, is generally of channel shape, and with the edges of the open side being defined by the channels 14, which, in turn, have their open sides facing in the same direction away from the concave side of strip 5 (FIG. 2).

The marginal portions of strip 4 along its longitudinally extending edges are rolled to form cylindrical beads -16 (FIG. 5) that project to the side of strip 4 opposite to its concave surface, and the spacing between beads 16 is substantially equal to the spacing between the open sides 15 of channels 14. The outside diameter of beads 16 is slightly less than the width of the open sides 15, and approximately equal to the inside diameter of channels 14 so that said beads may be sprung into the channels 14 through the open sides 15 to be tightly held in channels 14 (FIG. 6).

In forming each vane, the sound-absorbing, fireproof material, such as fiber glass batting 17, is readily inserted into the channel formed by strip 5 before the strip 4 is connected with strip 5. Inasmuch as the opening between channels 14 is almost the full width of the strip 5, it is apparent that the sound-absorbing material, which may be generally designated acoustical material may readily be positioned to fill the channel formed by strip 5 and compacted to substantially any desired degree, and strip 4 may then be positioned over said acoustical material and the beads 16 spring into the channels 14 for holding the strips 4, 5 together.

Any desired means may be employed for springing the beads into the channels 14, such as rollers or pressure applying elements 18 (FIG. 2), or the beads may be manually sprung into the channels 14. The application of the strip 4 after the acoustical material, which is compressible, is within the channel formed by strip 5, enables any desired degree of compression of said material 17.

The strip 5 is preferably perforated in the portion intermediate and spaced from edges 7, 9, as indicated at 19. Said latter portion includes the more pronounced part of its curvature, and the openings provide for dissipation of sound.

The concave surface of strips 4 is in continuation of the surfaces of marginal portions 10, 11 that face in the same direction, and these surfaces cooperate to define the air deflecting surface of each vane. Vanes 8 are usually assembled with rails 2, which rails may be formed with openings 20 (FIG. 4) that are adapted to register with the open ends of the hollow beads 16 when said vanes are positioned between the rails in the positions seen in FIGS. 1, 3. Nails or headed pins 21 (FIG. 4) are then driven through said openings into the open ends of the beads, and the gauge of the nails or pins is preferably such that they form a tight, frictional engagement with the inner sides of the beads, and may slightly expand the walls of the head to insure a rigid lock between the strips 4, 5 and rails 2. The outer surface of each nail 21 may be annularly grooved (FIG. 4) to form a row of annular teeth adapted to engage the inner surfaces of beads 16 to prevent loosening and withdrawal of the nails.

The material of the strips, being resilient, insures against loosening of the strips 4, 5, relative to each other and the rails and pins or nails 21, and the latter also may expand beads 16 to further insure a tight fit where strips 4 are coupled to strips 5.

It is obvious that the vanes may be secured in the elbow of a conduit to the sides of the latter, but generally the rails and vanes are initially secured together and the rails are thereafter secured to the opposite sides of the conduit. The marginal portions 22 of the rails are usually sprung slightly outwardly to tightly engage the opposite inner sides of the elbow 1, hence the heads of the pins 21 do not space the rails from the elbows, but are enclosed between portions 22.

The interengaging and locking means 14, 16 on strips 4, 5 not only provides a means for securing said strips together, but provides a means for securing the vanes in a duct or to the rails 2, and the provision of said locking means on the inner side of the vane, or the side that has the air deflecting surface, insures the stability of the vanes of this type in the duct or elbow.

I claim:

1. In an acoustical, hollow, air turning vane for installation within the bend of an air duct, which vane is of the type having opposite end edges and an inner wall and outer wall integrally connected along parallel edges extending between the ends of said end edges to provide a leading edge and a trailing edge respectively adapted to face into and away from air moving in one direction in said duct, said walls being progressively spaced apart in directions toward each other from said leading and trailing edges, and similarly curved to define an outer surface of generally airfoil contour in a plane normal to said leading and trailing edges with the outer surface of said inner wall being concave and the outer surface of said outer wall being convex, in said plane, the improvement comprising:

(a) said inner wall being formed with an opening extending from end-to-end of said vane for positioning acoustical material within said vane,

(b) said inner wall including a closure for said opening being a portion of said concavely curved surface, and means on said closure and on the inner wall outwardly of said opening for securing said closure in a closed position closing said opening with the concavely curved outer surface of said inner wall, including said closure, being substantially continuous between said leading and said trailing edges for a smooth flow of air across said last-mentioned surface from said leading to said trailing edges.

2. In a vane as defined in claim 1:

(c) said means on said closure and on said inner wall for securing said closure in said closed position being respectively adjacent to said leading and said trailing edges.

3. In a vane as defined in claim 1:

(c) said means on said closure and on said inner wall being in the space between said outer and said inner walls.

4. In a vane as defined in claim 1:

(c) a portion of said outer wall intermediate said leading and said trailing edge being perforated, and

(d) sound absorbent material within said vane between said inner and said outer walls and extending across the perforations of said perforated portion.

5. In a vane as defined in claim 1:

(c) said means on said closure and on said inner wall being respectively integral with said closure and said inner wall and projecting into the space between said inner wall and said outer wall, and in frictional interengaging, holding relation free from other independent elements such as clips, screws, rivets, and the like.

6. In a vane as defined in claim 1:

(c) said inner wall including a forward marginal por tion along said leading edge and a rear marginal portion along said trailing edge extending from said leading and trailing edges to said opening,

said inner wall comprising parts of said forward and said rear marginal portion along the edges of said opening bent to provide members projecting into the space between said inner and said outer Walls and having recesses facing said opening along opposite edges of the latter, and elements integral with said closure along said opening in positions and of edges of said vane, and from which supporting means each such fastener is adapted to project,

(g) said parts defining the sides of each of said recesses being resilient and the width of each slot in each part being slightly less than the maximum outside diameter of each of said elements to enable springing said elements past the edges of said slots and into said recesses.

external contours to enter the open sides of said recesses and to frictionally engage the lateral sides 10 (c) said leading edge being rounded and relatively of said recesses for holding said cover in said closed blunt, and said trailing edge being relatively sharp; position. and 7. In avane as defined in claim 6: (d) the space between said strips being greatest at (e) said parts on said inner Wall each being tubular a location closer to said leading edge than to said and open-ended providing opposite lateral sides of trailing edge. said recess extending longitudinally of said opening, and the open sides of each recess being an openended slot in one side of said part adjacent to edge of said opening, 2 685 936 (f) said elements each being tubular and openended 2989136 and extending parallel with said slots and one of the terminal open ends of said element terminating at ROBERT S. WARD JR Primary Examiner each of the end edges of sa1d vane for receiving a fastening element through each terminal open end thereof for securing each of said vanes to a vane 1g1 3 supporting means adapted to extend across said end 8. In a vane as defined in claim 1:

References Cited UNITED STATES PATENTS 8/1954 Brenneman et al. 6/1961 Wohlberg 181-42 XR US. Cl. X.R. 

